有难度吗？

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n; cin>>n;
    if(n<0) {cout<<"-";n=-n;}
    if(n%10==0) {n=n/10;}
    int sum=0;
    while(n!=0){
        int k=n%10;
        sum=sum*10+k;
        n=n/10;
    }
    cout<<sum<<endl;
    return 0;
}